I. Field of the Invention
The present invention generally relates to the field of workpiece holding devices, and in particular, the present invention is concerned with workpiece holding devices which include an expandable arbor having a thin shell that expands radially in response to a hydrostatic pressure imposed at the interior of the shell.
II. Description of the Prior Art
Workpiece holding devices having an expanding arbor which expands in response to a hydrostatic pressure imposed against a thin cylindrical shell are known. Examples of United States Letters Patents disclosing workpiece holding device utilizing a thin shell responsive to hydrostatic pressure are disclosed in U.S. Pat. Nos.: 1,818,042; 2,797,603; and 3,166,013. Examples of brazed joints wherein a thin shell is joined to a central body are disclosed in U.S. Pat. Nos.: 2,646,995 and 2,684,043 as well as disclosed in the U.S. patents listed hereinabove. None of the above listed U.S. patents disclose the support used by the present invention for the thin outer shell comprising thick wall ends and the use of chamfers to retain a copper ring for subsequent melting of the ring to form a seal and join the expandable sleeve to the central body.
III. Prior Art Statement
The aforementioned prior art, in the opinion of the Applicant and the Applicant's Attorney represents the closest prior art of which the Applicant and his Attorney are aware.